[Cervical lymph node metastasis and recurrence in supraglottic carcinoma after operation]

OBJECTIVE

To evaluate the regional control efficacy of elective neck dissection (END) in patients with supraglottic carcinoma.

METHODS

The incidence of cervical recurrences of 582 patients with supraglottic carcinoma treated in this hospital from 1981 to 1993 were retrospectively reviewed.

RESULTS

Three hundred and ninety-two cases (67.35%) of this group had T3 and T4 primary lesions. Among them, 147 cases (37.50%) had positive nodes(N+) and this accounted for 86.47% (147/170) of all N+ patients. Ipsilateral or bilateral cervical recurrence occurred in 33 of 126 (26.19%) node negative (N0) cases who had not had neck dissection and 30 of them (90.90%) were among T3 and T4 groups. However, Contralateral lymph node recurrence occurred only in 40 of 286(13.99%) N0 cases who had had END and 30 of them (75%) were among T3 and T4 groups. There were 163 cases who were readmitted and received surgery again for different purposes. The three and five year survival rates in the second stage END group were 86.67% and 77.78%, in metastasis group 64.81% and 32.50%, in recurrent group 33.33% and 30.77% respectively. There were significant differences in survival rates among these groups.

CONCLUSION

Patients underwent elective neck dissection achieved better survival than those on "wait and watch" policy and salvage surgery. Elective neck dissection is recommended for the treatment of supraglottic carcinoma, especially for the T3 and T4 diseases.

Metabolism of methyl tert-butyl ether and other gasoline ethers in mouse liver microsomes lacking cytochrome P450 2E1

To reduce the production of pollutants in motor vehicle exhaust, methyl tert-butyl ether (MTBE) and other ethers such as ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are added to gasoline as oxygenates for more complete combustion. Metabolism of these gasoline ethers is catalyzed by cytochrome P450 (P450) enzymes. P450 2E1, which metabolizes diethyl ether, was suggested to be an enzyme involved. The present study used 2E1 knock-out mice (2E1-/-) to assess the contribution of 2E1 to the metabolism of MTBE, ETBE and TAME. Liver microsomes prepared from the 2E1 knock-out mice lacked 2E1 activity (assayed as N-nitrosodimethylamine demethylation), but were still active in metabolizing all three gasoline ethers. The levels of ether-metabolizing activity (nmol/min per mg) in the liver microsomes from 7 week old female 2E1 knock-out mice were 0.54+/-0.17 for MTBE, 0.51+/-0.24 for ETBE and 1.14+/-0.25 for TAME at a 1 mM substrate concentration. These activity levels were not significantly different from those of the sex- and age-matched C57BL/6N and 129/Sv mice, which are the parental lineage strains of the 2E1 knock-out mice and are both 2E1+/+. Our results clearly demonstrate that 2E1 plays a negligible role in the metabolism of MTBE, ETBE and TAME in mouse livers.

[Genetic polymorphism and susceptibility to occupational chronic manganism: a case-control study]

OBJECTIVE

In a case-control study, the possible genetic factors relevance to occupational chronic manganism were investigated.

METHODS

Forty-nine manganisms who were welders and ferromanganese smelters occupationally exposed to manganese dust and fume from three metallurgical industries, and fifty unrelated healthy control subjects who were working same workshops were recruited. The subjects were matched for sex, age, cigarette and alcohol intake. The manganese exposure duration was also matched in this case-control study. Genetic polymorphism of cytochrome P450 2D6L (CYP2D6L) gene and NAD(P)H: quinone oxidreductase (NQO1) genes from all subjects were investigated. The mutations of CYP2D6L gene located exon 6 were analyzed by a polymerase chain reaction (PCR)-based DNA amplification combined with Hha I restriction fragment length polymorphism (RFLP). The substitution of 609(C-T) at exon 6 of DT-diaphroase gene was analyzed by PCR combined Hinf I RFLP.

RESULTS

The frequency of polymorphic allels, a mutation of CYP2D6, was significantly lower in patients with manganism (16.3%) than that of the controls (29.0%). A significant association was also found between the homozygote variant of CYP2D6L gene and occupational manganism. These results suggest that the CYP2D6 gene might be one of the susceptibility genes for Mn-induced neurotoxicity. The allele and genotype frequencies of NQO1 gene were similar in the manganism cases and control subjects.

CONCLUSION

It is possible that CYP2D6 gene may be a valuable susceptibility biomarker responded to Mn-induced central nervous system disorders in workers exposed to manganese.

[Relationship between the expression of transforming growth factor beta type I receptor (T beta R I) and prognosis of hepatocellular carcinoma (HCC)]

OBJECTIVE

To study the expression of T beta R I in HCC tissues and its clinical significance.

METHODS

Expressions of T beta R I in HCC tissues (HT, n = 30) and surrounding liver tissues(HST, n = 30) as well as four normal control liver tissues (CIT, n = 4) were determined by radioligand binding assay with 125I TGF beta 1 as the ligand. Relationships between some clinicopathological parameters of HCC and the relative expression rates of T beta R I in HCC were studied.

RESULTS

Compared with that in HST, the expression of T beta R I HT was significantly lower than in HST and CIT (P < 0.01). The expression of T beta R I in HST is similar to that in CIT. T beta R I relative expression rates in the group of no capsule or capsule invaded and in the group of tumor embolus were markedly decreased (P < 0.05). No close relationships were found between the T beta R I relative expression rate and age, sex, HBV infection, liver cirrhosis, AFP concentration, tumor diameter, tumor number, tumor differentiation as well as tumor embolus.

CONCLUSIONS

The low expression of T beta R I in HT may be one of the key event which promote the HCC malignant growth by protecting them against the growth inhibition effect of active TGF beta. The T beta R I relative expression rate may be related to the prognosis of HCC.

Identification of individuals at high risk for head and neck carcinogenesis using chromosome aneuploidy detected by fluorescence in situ hybridization

To visualize the accumulation of chromosome abnormalities in head and neck squamous cell carcinomas (HNSCC) and investigate the extension of the abnormal field, we applied the fluorescence in situ hybridization (FISH) technique to tumor cells and cells collected from a large extension of clinically normal buccal mucosa distant from the tumor in 10 patients. DNA probes specific for 14 human chromosomes (1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 15, 17, X, and Y) were used in dual-target, dual-color FISH assays. Control specimens were collected from oral mucosa of 10 healthy non-smokers, in order to define the tolerance limits for abnormalities, and from 10 healthy smokers. Extensive aneuploidy was detected in most of tumor specimens, more frequently represented by chromosome gains than losses. Interestingly, the clinically normal distant oral regions displayed chromosomal aneuploidies in seven out of the 10 patients tested. These findings support the occurrence of field cancerization in HNSCC. In addition, interphase FISH is demonstrated as an effective technique for detecting chromosome aneuploidy associated with malignancy and a potential tool for non-invasive screening of individuals at high-risk for HNSCC.

[Long-term follow-up result of partial laryngectomy in senile patients with laryngeal carcinoma]

OBJECTIVE

To study the long-term follow-up result of laryngectomy with reservation of laryngeal function in senile patients.

METHODS

Ninety-nine patients who were above 65 years old and underwent partial laryngectomies from 1986 to 1990 were summarized. Among them, 14 cases underwent vocal cord resection, 31 vertical hemilaryngectomy, 15 horizontal supraglottic hemilaryngectomy, 2 horizontal glottic laryngectomy, 22 horizontovertical (3/4) laryngectomy, 5 subtotal laryngectomy, 10 total laryngectomy with cricopharyngeal anastomosis.

RESULTS

All patients had their phonation and respiration restored. Decannulation rate was 91.9%. No death occurred during the operation. No severe postoperative complications were found. 3.5-year survival rates were 76.7% and 75.5% respectively.

CONCLUSION

Senility is not a contraindication for laryngectomy with reservation of laryngeal function. The key points are that surgeons should master indications correctly and improve surgical skill to decrease postoperative complications.

[A study on proliferation and differentiation of limbal stem cells]

OBJECTIVE

To study the proliferation and differentiation of limbal stem cells (LCs) in vitro and examine the effects of epithelial growth factor (EGF) on cell proliferation.

METHODS

The cells were cultured in DMEM/F12 medium. The proliferation and differentiation of cultured cells were studied by colony-forming efficiency (CFE), immunohistochemistry staining and Western blot examination.

RESULTS

LCs could be passaged 5 times in this culture condition. The CFE of stem cells was (5.07 +/- 2.35)%, while that of the central epithelial cells (CCs) was (1.12 +/- 0.86)%. The rates of freezing and recovery were (0.43 +/- 0.22)% in LCs and (0.16 +/- 0.07)% in CCs. Limbal stem cells could be stimulated to proliferate better by EGF at the concentration of 5 and 20 ng/ml. The staining of keratin 3 (K3) to stem cells in the primary culture was negative, but positive in the second and third passages. However, the expression of K3 by Western blot examination was positive in the primary and second passages but negative in the fourth one.

CONCLUSION

It is better for limbal stem cells to be used for transplantation and drug screening in the primary culture.

KCNQ2 and KCNQ3 potassium channel subunits: molecular correlates of the M-channel

The M-current regulates the subthreshold electrical excitability of many neurons, determining their firing properties and responsiveness to synaptic input. To date, however, the genes that encode subunits of this important channel have not been identified. The biophysical properties, sensitivity to pharmacological blockade, and expression pattern of the KCNQ2 and KCNQ3 potassium channels were determined. It is concluded that both these subunits contribute to the native M-current.

A mechanism underlying stimulation and inhibition of protein kinase C by lyso-PC: A role of membrane physical state

Lysophosphatidylcholine (lyso-PC) biphasically regulates the diacylglycerol-induced activation of protein kinase C (PKC). In common parlance, lyso-PC stimulates PKC at low concentrations, but, conversely, inhibits it at high concentrations. The activity of purified PKC from rat brains was measured in the vesicles made up of dipalmitoylphosphatidylserine (DPPS), 1, 2-sn-diolein (DOG) and different molar ratios of 1-palmitoyl-sn-glycerol-3-phosphoryl-choline (C16:0 lyso-PC). The effect, i. e. stimulation or inhibition on PKC by C16:0 lyso-PC, depends on DPPS and DOG concentrations as well as its own concentration. When the concentration of DOG is stable, this C16:0 lyso-PC action depends on C16:0 lyso-PCIDPPS molar ratio. Differential scanning calorimetry (DSC), two fluorescence probes and light scattering were used to analyze the physical characteristics of membrane, including thermotropic phase behavior, the turbidity, the lipid molecular acyl chains packing and the head group spacing. The more adulteration of C16:0 lyso-PC in liposome bilayer membrane, the looser acyl chains pack, and the broader head group spacing. DSC results show that there are two immiscible lipid areas in the membrane: C16:0 lyso-PC-rich area and C16: 0 lyso-PC-poor area. When C16:0 lyso-PC/DPPS molar ratio was 0.234, the two areas had the broadest boundary and the activation of PKC was the highest. When the ratio was over 0.434, the phase transition of DPPS disappeared; micelle tended to substitute the structure of bilayer; the activity of PKC was inhibited completely. DOG can stabilize the bilayer structure of membrane, so the C16:0 lyso-PC/DPPS molar ratios to inhibit PKC in lipid mixture with DOG are higher than that without DOG. The ability of C16:0 lyso-PC to change the physical properties and the structure of membrane plays an important role in its effect on PKC activation.

[Establishment of hybridoma secreting anti-mycobacteria monoclonal antibody by using electrofusion technique]

By using the electrofusion technique, the fusion of NS1 myeloma cells with spleen cells of BALB/c mouse immunized with five species of mycobacteria was carried out. With the optimal electrofusion conditions, we obtained a high fusion efficiency of 1.75 hybrid cell clones per 10(5) spleen cells. ELISA was used for screening secreting antimycobacteria McAb hybrid cells. After cloning, 22 stable hybrid cells lines were selected, and 8 of them had been studied.

[Laryngeal reconstruction after near-total laryngectomy]

OBJECTIVE

To reduce the rate of near-total laryngectomy and reconstruct laryngeal function.

METHOD

A retrospective review was made on 19 patients treated by near-total laryngectomy and laryngeal reconstruction from 1991 to 1996. Eight patients were male and 11 were female. The age range was from 40 to 74 years, with a mean age of 57.6. Two cases were in stage II, 9 cases stage III, 8 cases stage IV. The characteristic of this operation is to remove hyoid bone and reduce aspiration.

RESULTS

Speech function in all patients was good. Deglutition in most patients was good. Five patients breathed through the larynx after decannulation. Fourteen patients respired through tracheostoma because of stenosis of laryngeal cavity. Among them, 10 cases did not need cannula for their wide tracheostomas, 4 cases needed cannula. Three-year survival rate was 78.6%(11/14), 5-year survival rate was 75%(3/4).

CONCLUSION

Laryngeal reconstruction near-total laryngectomy is helpful to restore laryngeal function and decrease the rate of total laryngectomy.

DNase I hypersensitive sites in the chromatin of the chicken Msx2 gene differ in anterior and posterior limb mesenchyme, calvarial osteoblasts and embryonic fibroblasts

To identify candidate cis-acting regulatory regions involved in regulation of the Msx2 gene in anterior limb mesenchyme and calvarial osteoblasts, DNase I hypersensitive sites (DHSs) from -6.1 kb to +8.4 kb relative to the translation start site of the chicken Msx2 gene were identified in anterior and posterior limb mesenchyme, calvarial osteoblasts, and embryonic fibroblasts. A total of 12 DHSs were detected. Except for the DHS in the basal promoter region, none of the other DHSs were present in all four tissues, suggesting that the chromatin structure in the Msx2 gene locus is differently organized in these four cell types. One DHS was unique to Msx2 expressing cells and a second site to nonexpressing cells. Anterior and posterior limb mesenchyme had similar patterns of DHSs that were much more complex than observed in calvarial osteoblasts possibly reflecting differences in the complexity of Msx2 regulation in these two tissues.

Cloning of a mammalian elk potassium channel gene and EAG mRNA distribution in rat sympathetic ganglia

1. Three new members of the EAG potassium channel gene family were identified in rat and the complete coding sequence of one of these genes (elk1) was determined by cDNA cloning. 2. The elk1 gene, when expressed in Xenopus oocytes, encodes a slowly activating and slowly deactivating potassium channel. 3. The elk1 gene is expressed in sympathetic ganglia and is also expressed in sciatic nerve. 4. Six of the seven known EAG genes were found to be expressed in rat sympathetic ganglia, suggesting an important functional role for these channels in the sympathetic nervous system.

[TGF beta subtypes in hepatocellular carcinoma]

OBJECTIVE

To detect the expression of three TGF beta isoforms and its clinicopathologic significance in hepatocellular carcinoma(HCC).

METHODS

Surgical specimens of 52 patients with small HCC resection during 1992-1995 were used to determine the immunoreactivity of TGF beta protein by ABC immunohistochemistry. These specimens were divided into recurrence group(G1) and recurrence group(G2) according to whether HCC recurred two years after resection. The relations with recurrence of HCC were analyzed.

RESULTS

The positive rates in G1 and G2 were 85% (17/20) versus 47% (15/32) for TGF beta 1, 90% (18/20) vs. 78% (25/32) for TGF beta 2, and 45% (9/20) vs. 63% (20/32) for TGF beta 3. Significant difference was found in TGF beta 1 and TGF beta 2, but not in TGF beta 3.

CONCLUSION

The high immunoreactivity to TGF beta 1 or TGF beta 2 is positively related to the recurrence of HCC.

Malignancy detection by molecular cytogenetics in clinically normal mucosa adjacent to head and neck tumors

OBJECTIVE

To identify the potential use of chromosome imbalances as biomarkers for tumorigenesis in head and neck squamous cell carcinoma (HNSCC) by fluorescence in situ hybridization (FISH).

DESIGN

In this case-control study, chromosome copy numbers were assessed in dual-target, dual-color FISH assays using DNA probes specific for 14 human chromosomes (1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 15, 17, X, and Y) applied to exfoliated epithelial cells.

SETTING

University medical center.

PATIENTS

We examined 20 cell brushings (from 10 primary tumors and 10 clinically normal margins) collected from 10 patients with HNSCC and compared these with cell brushings from the oral cavity of 10 nonsmoker and 10 smoker control subjects.

INTERVENTION

None.

MAIN OUTCOME MEASURE

Chromosomal aneuploidy.

RESULTS

Specimens from nonsmokers displayed greater than 91% of cells with normal signals, indicating high analytical sensitivity for the probes. Specimens from smokers demonstrated large variability without significant imbalance (P>.05) compared with those from nonsmokers. Tumor specimens from patients with HNSCC displayed significant chromosomal imbalance (P<.05) for all probes except chromosome Y. Similar imbalance, although in lower frequency, was found in all clinically normal adjacent mucosa specimens.

CONCLUSIONS

Interphase FISH demonstrated great applicability in detecting chromosome imbalance associated with malignancy in HNSCC and clinically normal adjacent cells, thereby detecting subclinical tumorigenesis. A panel of chromosome probes (chromosomes 3, 8, 9, and 10) is proposed as an efficient and sensitive additional tool for future routine screening of tumor margins and potential diagnosis of residual disease in HNSCC.

[Investigation of the clinicopathologic features, immunophenotype and Epstein-Barr virus infection of the upper respiratory tract lymphomas in patients]

OBJECTIVE

To study the clinicopathologic features, immunophenotype and Epstein-Barr virus (EBV) infection of the upper respiratory tract lymphomas in patients from north China.

METHODS

112 cases of upper respiratory tract lymphomas in patients from north China were investigated. HE stain for histologic features. Immunohistochemistry studies were performed using monoclonal antibodies, UCHL-1 for T-lymphocyte, L26 and 4KB5 for B lymphocyte, CS1-4 for latent membrane protein-1 (LMP-1). In situ hybridization for EBV encoded small nuclear RNA (EBER 1/2, Y017, DAKO).

RESULTS

77/112 cases (68.75%) were T-cell lymphomas, 35 cases (31.25%) were B cell lymphomas. EBV-EBER 1/2 in situ hybridization positive in 54/101 (53.46%) cases, including 48 T-cell lymphoma cases and 6 B-cell lymphoma cases.

CONCLUSION

Most upper respiratory tract lymphoma cases in patients from north China are T-cell lymphomas and are strongly associated with EBV.

Aspirin inhibition and acetylation of the plant cytochrome P450, allene oxide synthase, resembles that of animal prostaglandin endoperoxide H synthase

The enzymatic reactions leading to octadecanoid lipid signaling intermediates in plants are similar to those of animals and are inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs) such as salicylic acid and aspirin. In animals, NSAIDs inhibit the cyclooxygenase (COX) activity of prostaglandin endoperoxide H synthase, which ultimately blocks the formation of prostaglandins. In plants, NSAIDs block the formation of 12-oxo-phytodienoic acid and jasmonates, which are the equivalent signaling compounds. In this study we show that NSAIDs act as competitive inhibitors of allene oxide synthase (AOS), the cytochrome P450 that initiates plant oxylipin synthesis. We also show that aspirin causes the time-dependent inhibition and acetylation of AOS, which leads the irreversible inactivation of this enzyme. This inhibition and acetylation superficially resembles that observed for the inactivation of COX in animals. In AOS, aspirin acetylates three serine residues near the C-terminal region that appear to be highly conserved among AOS sequences from other plants but are not conserved among "classical" type P450s. The role of these serine residues is unclear. Unlike animal COX, where acetylation of a single serine residue within the substrate channel leads to inactivation of prostaglandin endoperoxide H synthase, the three serine residues in AOS are not thought to line the putative substrate channel. Thus, inhibition by aspirin may be by a different mechanism. It is possible that aspirin and related NSAIDs could inhibit other P450s that have motifs similar to AOS and consequently serve as potential biochemical targets for this class of drugs.

Epidemiological survey on clonorchiasis sinensis in Yangxin County of Hubei Province of PR China

An epidemiological survey of clonorchiasis was conducted at Panqiao township of Yangxin County of Hubei Province from June to November, 1993. The positive rate of cercaria in the body of intermediate hosts, Parafossarulus stratulus and Alocinma longicornis was 12.25% and 3.84% respectively. Positive rates of metacercariae in the bodies of Pseudonaphona parva was 48.15%, Ctenopharyngodon idellus 17.24% and Hypophthalmichthys nobilis 18.18%. Positive rate of eggs in the feces of cats was 36.36% and pigs 16.67%. It has been confirmed that there is a natural focus of clonorchiasis sinensis at Yangxin County of Hubei Province. A total population of 6,865 in 20 sites of 10 production brigades of Panqiao township was surveyed for infection with Clonorchis sinensis. The average infection rate in the local residents was 5.80%. Male had a higher infection rate than female. The infected persons were mainly peasants and school girls and boys. Most of the infected persons had light infections (I0) without a serious clinical manifestations.

Glycophorin variants and contents of sialic acid and total sulfhydryl groups on erythrocyte membranes of residents in a malaria hyperendemic area

OBJECTIVE

To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province.

METHODS

GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS-PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively.

RESULTS

Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group; while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72). The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P < 0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P < 0.05).

CONCLUSIONS

The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.

[Histopathological study of local invasiveness of transglottic cancer]

OBJECTIVE

To explore the characteristics and relevant factors of transglottic cancer invading paraglottic space (PGS) and pre-epiglottic space (PES).

METHODS

Whole-organ serial sections of 50 transglottic cancer specimens were studied histopathologically.

RESULTS

Transglottic cancer invading PGS was observed in 39 of the 50 (78.0%) specimens. In 32 of the 39 specimens, the invasion outstripped PGS, involving elastic cone in 26(81.3%), thyroid cartilage in 24(75.0%) and cricothyroid membrane in 20(62.5%). Transglottic cancer invading PES was seen in 23 of the 50 specimens (46.0%). With the increase in tumor staging and tumor size, PGS and PES became increasingly invaded. There were two possible routes of invasion to PES: a) extending anteriorly and upward via PGS; b) extending upward via anterior commissure to destroy the stem of epiglottic cartilage.

CONCLUSION

PGS is easily invaded by transglottic cancer. Partial laryngectomy is recommended in patients with T3, T4 transglottic cancer larger than 20 mm in diameter.

Peptide mass fingerprint sequence coverage from differently stained proteins on two-dimensional electrophoresis patterns by matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS)

Identification of proteins separated by two-dimensional electrophoresis (2-DE) is a necessary task to overcome the purely descriptive character of 2-DE and a prerequisite to the construction of 2-DE databases in proteome projects. Matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) has a sensitivity for peptide detection in the lower fmol range, which should be sufficient for an analysis of even weakly silver-stained protein spots by peptide mass fingerprinting. Unfortunately, proteins are modified by the silver staining procedure, leading to low sequence coverage. Omission of glutaraldehyde increased the sequence coverage, but this improved sequence coverage is still clearly below the sequence coverage starting with Coomassie Brilliant Blue (CBB) R-250-stained spots. Other factors additionally seem to modify proteins during silver staining. By decreasing the protein amount, the advantage of very sensitive detection on the gel is lost during identification, because the resulting low sequence coverage is not sufficient for secure identification. Low-quantity proteins can be identified better starting with CBB G-250 or Zn-imidazol-stained proteins. In contrast, for high-quantity CBB R-250-stained spots, a sequence coverage of up to 90% can be obtained by using only one cleaving enzyme, and up to 80% was reached for medium-quantity spots after combination of tryptic digest with Asp-N- and Glu-C digest.

[Quality control for huoxiang-zhengqi liquid]

The Rhizoma Atractylodis, Cortex Magnoliae Officinalis and Pericarpium Citri Reticulatae in Huoxiang-zhengqi Liquid were identified by TLC. The total contents of magnolol and honokiol were determined by HPLC to be no less than 1.9 mg/ml, with an average recovery of 104.4% and 103.3%, RSD 1.23% and 0.91% respectively.

Effects of different subtypes of histamine receptors on proliferation and differentiation of murine colony forming unit granulocyte-macrophage and colony forming unit megakaryocyte

OBJECTIVE

To investigate the function and characteristics of histamine receptors on the hemopoietic progenitor cells.

METHODS

BDF1 mice (both male and female), inbred at our university, aged 8-12 weeks, weighing 20-24 g, were used in this study. Bone marrow cells were incubated for 1 hour at 37 degrees C with 2-AT (H1 receptor agonist) or impromidine (H2 receptor agonist) alone, or in combination with the antagonists pyrilamine or cimetidine respectively. Control experiment was performed in Dulbecco's modified Eagle's Medium (DMEM) alone. Cells treated with different drugs were performed by colony forming unit-granulocyte-macrophage (CFU-GM) and colony forming unit-megakaryocyte (CFU-Meg) assay.

RESULTS

When bone marrow cells were treated with 10(-8) mol/L to 10(-5) mol/L of 2-thiazolylethylamine (2-AT) which had no influence on CFU-GM and CFU-Meg proliferation, 10(-8) mol/L to 10(-5) mol/L of impromidine could increase the number of CFU-GM and CFU-Meg colonies. The effects of H2 receptor agonists on CFU-GM, CFU-Meg could be antagonized by H1 receptor agonist.

CONCLUSIONS

Our findings suggest the existence of histamine H1 and H2 receptors on the hemopoietic progenitor cells and the antagonism between two different histamine receptor subtypes on the proliferation of CFU-GM and CFU-Meg.